This invention relates to the fabrication of plated articles and, in particular, to a method of monitoring the solutions used to plate such articles.
In the fabrication of printed circuit boards, complete coverage of certain areas by an electroless copper plating operation is an essential step. Unfortunately slight changes in the composition of the solutions required for electroless plating can have a significant effect on the coverage. Consequently, the solutions should be constantly monitored.
Present wet chemical analysis and backlight measurements have generally proven insufficient in either predicting problems or in identifying the cause of problems once they manifest themselves. This has resulted in enormous waste in terms of time and material until the problem is corrected. For example, in a typical printed circuit board fabrication process, it may take several hours for a particular board to traverse the various solutions used for electroless plating. Consequently, the effect of any adjustments in the solutions on the coverage of the board will not show up for a long time.